Gyroscopically-stabilized inclinometer



Oct.. 29, 1929. H. A. BORRESEN GYROSCOPICALLY STABILIZED INCLINOHETER Qriginal Filed Oct. 28. 1918 3 Sheets-Sheet Oct. 29, 1929. H. A. BoRREsEN 1,733,109

GYROSCOPICALLY STABILIZED I'NCLIOHETER Original Filed Oct. 28. 1918 5. Sheets-Sheet 2 [Egg 5 fw Oct. 29, 1929. H. A. BoRREsEN 1,733,109

GYRQSCOPICLLY STBILIZED INCLINOMETER Original Filed Oct. 28. 1918 3 Sheets-Sheetl jme/r 1&2/

Patented oa. 29, 1929 d y n v1,733,109

UNITED STATESl PATENT oFFIcE HELGE A. BORRESEN, F CHICAGO, ILLINOIS i GYROSCOPICALLY-STABILIZ'ED INCLINOMETEB -Application led October 28, 1918, YSerial No. 259,910. Renewed March 13, 1986.'.y

My invention relates to indicating instrugraduations marked on the magnetic disc of ments and has to do more particularly withV the compass inside the globe;

devices of this character adapted for indi Fig. 8 is a modiied arrangement for supcating the inclination to the horizontal of a porting the gyroscope for automatic adjust 5, traveling object'such as an aeroplane, Subment thereof;' 55

marine-boat, etc., it being also adapted forv Fig. 9l is a modification showing the' indiuse in supporting and stabilizing Compasses. cator combined with a magnetic needle and My invention is particularly yuseful in conf degree reading disc; nection with aeroplanes for indicating the Fig. 10 is a section along the line 10, 10 of 10 angle of inclination to the horizontal, show- Fig. 9 showing a' method of supporting the 60 ing for example, whether the aeroplane is compass needle and degree disc; and traveling to the right, left, upwardly or Fig. 11 is a detailed view showing that the downwardly, or in any `resultant direction. rings may be narrowed down so as to reduce To this end I provide an indicating device weight and obscure less of the instrument.

, 915 adapted to remain in a substantially level po- Referring now to the preferred form of my 05 sitien regardless of the direction of travel invention as shown in Figs. 1 to 7 it includes of the aeroplane, preferably using a device an outer support or' mounting in the form of supported by a so called gimbal caring or a graduated ring 15 adapted for attaching universal joint which in the preferred emthe instrument to the cowl or instrument ac bodiment includes two sets offbearings in board on the aeroplane, or whatever it may 70 one plane and athird bearing vertical thereto. be used with, although, of course, it isto be In order to maintain the device substantially understood that other mountings may be level I provide a motor driven gyroscopic used .depending upon how the instrument is element which I preferably mount Within thev to be attached. Supported in the vertical inner ring or support and with its axis of roaxis'16, 16 in the ring or frame 15 is a movable 75 tation in a horizontal plane and transverse support in the form of an outer ring 17 which n to the direction of travel. in turn carriesan intermediate ring 18 upon For a better understandingof my invena horizontal axis 19, 19 and supported within tion reference is to be had to` the' accomthis intermediate ring 18 is an inner gyro- 39 panying' drawings in which scopic support preferably in the form of a 80 v Fig. 1 is a face view of the instrument but globe A pivoted upon the axis 21, 21 in the in section along line 1, 1 of Fig. 4; same plane as the axis 19, 19. Thus the inner Fig. 2 is a sectional view along the line and intermediate rings 01- Supports are pref- 2,2' of Fi ..1 showing a jewel bearing superably supported upon axes in the same plane port fort e compass needle and magnetic and the intermediate ring in turn is 'support- 8.5

disC; V ed upon an axis perpendicular thereto. Fig. 3 iS a SectOn along the line 3, 3 Of From the general explanation so far given 'Fig'. 2 ShOWIlgthe eWel 1'01161' bearing fOr it will be apparent that the inner gyroscopic the Compass Shaft; i support A is universally mounted so that it 40 Fig- 4 is a Side View 0f the indicator with may be maintained in a denit'e position re- M its outer protection insection and mounted gardless of any position the supportV 15 \in thefcowly may take.

Fig. 5 is a transverse section along the line N-ow in order that the inner element A, 5, 5 of Fig. 4; which it might be said acts as the station- Fig. 6 iS a detailed View 0f an insulated ary element or indicator for the instrument, 9 bearing through which the connection to may be held stationary and uniniiuencedby the gyroscope motor may extend; the inclination ,of the support 15,1 p rovlde Fig. 7 is a plan view of the top of the globe a gyroscopic element 23 preferably in 'the or stationary element of the indicator, showforni of an electrically driven device rigldly ing the graduations marked thereon and the attached to the stationary indicator A prefer- 100 l ably by an adjustable mounting 24 and base 25, which in the form ofmy invention shown in Figs. 1 to 7, acts to assist in maintaining the member A in a normal position when the device is acting` and also assures the maintenance of the indicating member A in its normal position when the gyroscope is at rest and the aeroplane stationary so that in starting, the indicator is in proper position.

So far I have simply described in general the arrangement and disposition of the parts. Now as to the detailed construction, the inner support or stationary indicating element A is preferably in the form of an 0verweighted or unbalanced hollow spherical framework vconsisting of a metallic base 27 and transparent top, preferably in the form of a glass section 28 suitably secured to the base 27 at the line 29. Supported by the base 27 is a motor 23 which is carried by the ad- Iinstable standard comprising parts 24 and 25, the base 25, which in this form of my invention acts to unbalance the globe, being f securely fastened to the portion 27 in a suitable manner. It is to be understood, however, that the motor and gyroscope may be llowered on alight standard 24, so that they1 act as the'weioht to unbalance the globe A instead of depending upon the eXtra weight of the standard thus lightening the device and also placing the motor farther away from the compass needle. The gyroscopic element 23 is electrically driven and may consist of a suitable motor carrying ily wheels 30, 31 attached upon opposite ends of the motor shaft, thesefly wheels being preferably cupped so as to extend over the ends of the motor frame thereby securing weight and at the same time a more compact device. The motor shaft preferably has some longitudinal play, this being for the purpose of providing a brake action effective at certain times as will be hereinaftermore fully explained. This brake mechanism, as shown more 'clearly in Fig. 5, consists of suitable adjustable stationary brake shoes 32, 33 which are adapted to engage the outer faces of the -fly wheels 80, 31 when the action of the aeroplane is such as to throw the motor shaft to one side or the other by centrifugal force as when the aeroplane is turning toward the right or left. It will be noted that a pair of springs 34, 35 are provided which maintain .the motor normally in an intermediate position. If the advance of the aeroplane is such as to throw the shaft toward the right as for example, when the aeroplane is traveling to 4the left, the brake shoe acts upon the fly wheel the motor and 31 to retard the rotation o decrease its speed. This action is for the purpose of reducing the gyroscopic effect under certain conditions as will be hereinafter more fully pointed out. To vthe contrary, when the motor shaft is forced in the opposite di- 65 -rection, the brake shoe 32 acts upon the fiy brake shoes 32, 33 are adjustable so that they may be moved not only toward and away from the fly wheels but the contact points are also radially adjustable upon their supporting arms so as to secure the proper. cooperation between the parts. Referring now to the transparent or upper part 28 of the globe A, this is graduated at the lines 37 preferably to indicate degrees of inclination to horizontal, these graduation lines being shown more clearly in Figs. 4 and 7. This indicating part of the globe A may also be marked in other suitable ways. as Up and Down so that the aviator may know at a glance the direction of travel and the degree of inclination. vThe blackened spot on the'top of the globe A also assists in more readily determining the general inclination.

Now in addition to the angle indicator I may also provide a compass which consists of a magnetic disc element in the form of a spherical disc 38 which is suitably magnetized so as to act as a compass disc and rotatably supported preferably in a manner as more clearly shown in Figs. 2 and 3. This supporting means consists preferably of a tube 39 which may be threaded into the-motor frame and carries a shaft or spindle 40 preferably of non-magnetic material suitably attached to the disc element 38 at the top and carrying a hardened steel point 41 supported 'in an oil containing jewel bearing consisting of a base jewel 42and hollow jewel bearing 43 which is cupped out to act as an oil retainer. It is also to be noted that the extremity of the shaft 41 is rounded so as to .105

have only a slight point of contact, the end and side bearings being so proportioned that the frictional retardation upon the needle spindle 40 is the same regardless of the position of the compass. That is the frictional w the comparatively small shafts 45. A dust cup 72 is provided for enclosing and protecting vthis bearing'.

It will thus be apparent that I have pro- 'vided a compass bearing which rotates practically without friction and in which the frictional resistance is practically constant.. IThe magnetic disc 38er' needle by locating the two bearings and 61 remotely apart is caused to rotate in a definite plane and there# fore in consistent and contiguous relation to the reading registers eti'ecting'accurate reading. The point 62 prevents shaft 40 from dislodgment in bearing A by the proximity of glass 28.

Now as to the lntermediate support for the device. as already stated this includes the ring 18 which supports the innerelement A path through the bearings to the gyroscope motor. This bearing as shown in Fig. 6 comprises a sleeve 47 passing through the shell 27 and having a ball race co-operating with the ball rac-e 48 carried by the ring 18. An

insulating sleeve 49 is inserted between the binding post 50 and the sleeve 47 so that current may be conducted from the binding post 50 to a conductor 51 adapted to lie in the slot 52 on the inner surface of the shell 27.

By this construction it will be seen that an insulated ball bearing joint is provided, one which although providing a conductive path therethrough is insulated from the rest of the device. It is to be understood that bearings of this type are to be used at the requisite bearings so as to provide an insulated conductive path from the interior of the device to the gyroscope motor. The return path is through the frame. At the various pivotal bearings in the rings I have merely shown a small threaded stud but it is to be understood that this' is merely for diagrammatic purposes and that suitable ball bearings, some of which are insulated are to be provided so as to have an easily operable device.

The outer support 17, which carries the intermediate ring 18 is also preferably a ring supporting the intermediate ring 18 at the bearings 19, 19 preferably in alignment .With'the bearings 21. 21 and the motor axis,

so that we have these three axes positioned preferably parallel to each other and which in the preferred form of my instrument are normally horizontal planes. One of the bearings 19 is an electrical ball bearing connection while the opposite bearing mav be a cone bearing and this system is provided at the various gimbal bearings for purposes of adjustment and assembling.

This ring 17 which normally lies in a vertical plane also co-operates with the indicator globe A to indicate the inclination of the aeroplane to the horizontal, the frontedge of the ring 17 being in line with the axis-of the bearings 19, 19 and 3o-operating with {tl-ie` graduations 37 on the upper part of th'eiindi-c'ator A to show the inclination to the'h'orizontal. rFlins it will be apparent, that with the aeroplane moving forwardly as indicated by the arrows in Figs. 4 and 5, should the machine be driven upwardly the indicator A will remain comparativel stationary but the upper half of the ring 1 would move toward the front of A, in the direction marked Up on the globe as shown in Fig. 7, the front edge of the ring 17 indicating the exact angle of inclination by the degrees marked upon the globe A. Should the aeroplane be driven downwardly the front edge of the ring' 17 would move toward the rear of the indicator A likewise showing the degrees of downward inclination.

This outer ring 17 which it will -be noted is also pivotally supported, is Icarried by the frame 15 and rotatably mounted in the bearings 16, 16. Thus it will be seen that the axis of rotation for the outer ring 17 is perpendicular to the other .two axes of rotation of the universal joint but the rotary movement of this outer ring 17 is la limited one, being determined by theyielding connection 54 which permits but a slight movement of the ring 17 so that during certain maneuvers of the aeroplane, as for example abrupt side turns, there is no sudden jar to the controlling mechanism as this yielding connection 54 acts as a sort of a buffer to prevent undue shock displacement of the gyroscope.

Operation of Figs. 1 to 7' Having described the construction of my invention as shown in Figs. 1 to 7 I will now take `up its operation. Assuming the device is constructed for use in an aeroplane, it is mounted in the cowl orinstrument board with the device facing the operator as shown in Fig. 1. In starting out, the instrument is in the position indicated due to the overweighting or unbalancing of the partsA as appears from Fig. 1.l The motor of the gyroscope is then started, the fly wheels rotating in the direction indicated by the arrows in Fig. 8, that is, sothat the top of the ily wheels are moving away from thel operator. The gyroscopic e'ect is, of course, thus brought about. As the plane moves forward in a horizontal position the indicator ofcourse remains relatively stationary but assuming that the operator, after attaining some height, inclines the aeroplane upwardly at quite an angle the unbalanced eiect of the inner globe tends to maintain the globe A in practically a constant level position. Therefore the indicating edge of the ring 17 moves around toward the front of the globe A due to the pivotal bear# ings 19, 19 and the operator can by not-ing the reading on the graduations 37 of the upper part of the indicator A, tell at a lance that he'is traveling upwardly and also t e degree of inclination. Now assuming that `while the operator is traveling upwardly he points his machine toward the right, the gyroscopic action will then counteract the centrifugal disturbance imparted to the unbalanced globe. In this case the indicator A will follow the aeroplane, remaining stationary K -relative thereto except for such slight mo'l v mentary lag permitted bv the yielding con-.

' nection 54 at the bottom ofthe ring 17. That y position.

Assuming now that the machine continues c its advance at the same upward inclination but starts -to turn bodily as in the direction of a right handed screw-thread. Immediately the gyroscopic effect is such that the indicator globe A remains practically level,

turning upon the pivots 21, 21 in the-ring 18 as the plane rotates. 25

This movement is therefore immediately indicated bv the graduations upon the indicator frame 15, the heavy line 56 uponthe globe A moving along the frame 15 toward the left and indicating to the opera-tor that he is rotating bodily toward the right, the 4device also indicating the angle of inclination as alreadyl described. If the operator makes a complete half turn so that. he is moving forwardly up-side-down, it will be apparent that the line 56would be at the bottom of the ring 15. It will thus be apparl ent that the operator cantell at a glance the exact direction of travel by noting the posi* tion of the indicating edge of the ring 17 on the graduations 37, and noting the position of. the line 56 on the globe A relative to the `graduations on the outer frame or ring 15.

Now in addition to the fact that the device indicates the angles of inclination, the comass will show the general direction of travel y means of the magneticv disc 38 always maintaining a north andI south position. Thus the operator can tell by the relative positions of the so-called lubberline 56 and graduations upon the magnetic disc 38, the general direction of travel.

In the above description of operation I referv to certaindirections of travel and it, of course, will beapparen't that in traveling in directions opposite to those described the indicator will work just oppositely.

Now in connection with the general operation and arrangement of my invention'vs shown in Figs. 1 to7g11have found that by .having the axis of the gyroscope in a horizontal plane and transverse to the direction of travel,I a control of the device is secured diiierent than when the axis lies in a vertical plane. That is, with a transverse horizontal axis, the gyroscopic effect is the same whether the aeroplane turns to the right or to the left. I have found that with the groscc'pe traveling in the direction of the arrows 1ndicated thereon, that is, what might be said with the machine, there is a tendency to oppose the centrifugal force acting to'throw the unbalanced or overweighted part ofthe indicating globe A 4outwardly when thema'-B chine is .taking a' right or left` turn.l The gyrosc'opli:1 effect neutralizes the centrifugal force. 1 at is, assuming the aeroplane is .,v

moving forward ona right turn, without the gyroscope and with only the overweightedl or unbalanced globe, the overweighted art of the globe would swing outwardly att e bottom on the pivots 21, 21. By having the gyroscope rotate with the machine as inicated by the arrows, this centrifugal force is neutralized by a properly proportioned gyroscopic action By operating the gyroscope with the machine it is a question of vproperly proportioning the weight and angular velocity of the gyroscope and degree of imbalance, torproduce a neutralizing effeet upon the. centrifugal force sufficient to maintain the indicating globe A in a practically level position. .Now thisl centrifugal force, of courseq also varies with a varia tion in the angular velocity of the machine in making a turn as to the right or left and in order to accommodate for this variation, I provide the brake mechanism 32, 3 3 which acts to retard the speed of rotation of the gyroscope as the angular velocity of the aeroplane increases. This may be found desirable due to the fact that the aeroplane in making abrupt turns to the right or left, causes a tendency on the part of the gyroscope to climb or act opposite'to the action of the weighted member. Therefore, tie angularvelocity of the gyroscope may be decreased to a point where it more nearly neutralizes the centrifugal force tending to throw the overweight part of globe A outwardly.

' Fig. 8

In Fig. 8 I have shown a modified form of my invention illustrating another method of shifting the transverse balance of the gyroscope for the purpose of decreasing the gyroscopic effect when the aeroplane turns to the right or to the left. This is for thesame purpose yas the brake mechanism shown in Fig. 5 except that in Fig. 8 intseadv of slowing down the gyroscope to neutralize the centrifugal force I shift the balance, moving the iy wheel 30, 31 to the right or left as the case may be. In order to accomplish this I provide a pendulum 63 pivoted in a slotin the standard'Q at 64 and connected at 65 to a slidable shifting device 66 which carries rollers engaging the fly wheels 30, 31. Thus assuming the aeroplane turns toward theright, the pendulum 63 will swing toward the left thereby shifting the fly wheels 30, 31 toward the right so as lto decrease the gyroscopic effeet. yIt will be noted that the Hy wheels are adjustable upon the motor shaft and may be moved along the shaft to vary the gyro scopic effect.

Another modification shown in Fig. 8 is the use of an unbalanced or over-Weighted ring 18 which, due to its construction, will assist in maintaining this ring' 18 in its proper position.

Figs. 9 and 10 vrotating within the `iewel roller bearing 68 having a construction similar to that shown in Fig. 2. The sleeve 39 carries a degree in dicator ring 69 which may be observed through the transparently closed opening 70. It will thus be apparent that by providing the compass construction illustrated and us ing it in connection with the gyroscopic stabilizer, I have a compass which remains practically level at all times regardless of the inclination of its support. In this form of device the general direction. is indicated by the needle while the degrees are read on the disc of large diameter.

Fig. 11

In Fig. 11 I have shown a modified form of ring construction wherein instead of using a gimbal ring of the same width, I provide a ring 182 narrowed down at 183 so that I not only reduce the weight of the device, which, of course, at times is important, but also remove parts of the device which might otherwise obscure the indicating system and prevent a ready observation of the graduations at all times.

I claim:

1. A device of the character described, comprising a support, adapted for mounting upon a moving body, and means carried by said support for indicating the angle of inclination of said moving body relative to a horizontal plane both in the direction of travel of said body and transversely of its direction of travel comprising a spherical framework, means universally mounting said framework in said support, cooperating indicating devices on said support and framework, a gyroscopic element mounted for rotation about a horizontal axis in said framework, the center of gravity of said framework and element being below the horizontal axis of support of said framework and means for rotating said element so that the upper side thereof moves in the general direction of movement of said moving body.

2. A device of the character described for indicating the inclination of an aircraft to the horizontal both in the direction of its travel and transversely thereto comprising a support adapted to be secured to said craft, a framework, means universally mounting said framework on said support whereby it may swing relative to said support about an axis parallel to the direction of travel of said craft and about a transverse axis extending at right angles to the direction of travel of said craft, said framework having its center of gravity below the supporting axis thereof, a single gyroscopic element mounted for rotation `in said framework about a horizontal axis extending transversely to the direction of travel of said craft, means for rotating said element so that the upper side thereof moves in the direction of travel of said craft, and means for indicating the inclination of said support to said framework.

In witness whereof, I hereunto subscribe my name this 22nd day of October, A. D.,

HELGE A. BORRE SEN. 

